diff --git a/package.json b/package.json
index 922cd8a..78ef127 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,7 @@
 {
-  "name": "purescript-csv-stream",
+  "name": "purescript-node-stream-pipes",
   "version": "v1.0.5",
+  "type": "module",
   "dependencies": {
     "csv-parse": "^5.5.5",
     "csv-stringify": "^6.4.6"
diff --git a/spago.lock b/spago.lock
index 8fc8228..693f747 100644
--- a/spago.lock
+++ b/spago.lock
@@ -9,6 +9,8 @@ workspace:
         - either: ">=6.1.0 <7.0.0"
         - exceptions: ">=6.0.0 <7.0.0"
         - foldable-traversable: ">=6.0.0 <7.0.0"
+        - foreign-object
+        - lists
         - maybe: ">=6.0.0 <7.0.0"
         - mmorph: ">=7.0.0 <8.0.0"
         - newtype: ">=5.0.0 <6.0.0"
@@ -18,6 +20,7 @@ workspace:
         - node-path: ">=5.0.0 <6.0.0"
         - node-streams: ">=9.0.0 <10.0.0"
         - node-zlib: ">=0.4.0 <0.5.0"
+        - ordered-collections
         - parallel: ">=6.0.0 <7.0.0"
         - pipes: ">=8.0.0 <9.0.0"
         - prelude: ">=6.0.1 <7.0.0"
@@ -25,6 +28,8 @@ workspace:
         - strings: ">=6.0.1 <7.0.0"
         - tailrec: ">=6.1.0 <7.0.0"
         - transformers: ">=6.0.0 <7.0.0"
+        - tuples
+        - unordered-collections
         - unsafe-coerce: ">=6.0.0 <7.0.0"
       test_dependencies:
         - console
@@ -105,6 +110,7 @@ workspace:
         - type-equality
         - typelevel-prelude
         - unfoldable
+        - unordered-collections
         - unsafe-coerce
         - variant
   extra_packages: {}
@@ -903,6 +909,21 @@ packages:
       - partial
       - prelude
       - tuples
+  unordered-collections:
+    type: registry
+    version: 3.1.0
+    integrity: sha256-H2eQR+ylI+cljz4XzWfEbdF7ee+pnw2IZCeq69AuJ+Q=
+    dependencies:
+      - arrays
+      - enums
+      - functions
+      - integers
+      - lists
+      - prelude
+      - record
+      - tuples
+      - typelevel-prelude
+      - unfoldable
   unsafe-coerce:
     type: registry
     version: 6.0.0
diff --git a/spago.yaml b/spago.yaml
index da7051b..76b1a72 100644
--- a/spago.yaml
+++ b/spago.yaml
@@ -10,6 +10,11 @@ package:
     strict: true
     pedanticPackages: true
   dependencies:
+    - foreign-object
+    - lists
+    - ordered-collections
+    - tuples
+    - unordered-collections
     - aff: ">=7.1.0 <8.0.0"
     - arrays: ">=7.3.0 <8.0.0"
     - effect: ">=4.0.0 <5.0.0"
diff --git a/src/Node.Stream.Object.js b/src/Node.Stream.Object.js
index c3b6a63..5f85aa1 100644
--- a/src/Node.Stream.Object.js
+++ b/src/Node.Stream.Object.js
@@ -1,35 +1,39 @@
 import Stream from "stream";
 
 /** @type {(s: Stream.Readable | Stream.Transform) => () => boolean} */
-export const isReadableImpl = s => () => s.readable
+export const isReadableImpl = (s) => () => s.readable;
 
 /** @type {(s: Stream.Writable | Stream.Readable) => () => boolean} */
-export const isClosedImpl = s => () => s.closed
+export const isClosedImpl = (s) => () => s.closed;
 
 /** @type {(s: Stream.Writable | Stream.Transform) => () => boolean} */
-export const isWritableImpl = s => () => s.writable
+export const isWritableImpl = (s) => () => s.writable;
 
 /** @type {(s: Stream.Readable | Stream.Transform) => () => boolean} */
-export const isReadableEndedImpl = s => () => s.readableEnded
+export const isReadableEndedImpl = (s) => () => s.readableEnded;
 
 /** @type {(s: Stream.Writable | Stream.Transform) => () => boolean} */
-export const isWritableEndedImpl = s => () => s.writableEnded
+export const isWritableEndedImpl = (s) => () => s.writableEnded;
 
 /** @type {(s: Stream.Writable | Stream.Transform) => () => void} */
 export const endImpl = (s) => () => s.end();
 
 /** @type {<WriteResult>(o: {ok: WriteResult, wouldBlock: WriteResult, closed: WriteResult}) => (s: Stream.Writable | Stream.Transform) => (a: unknown) => () => WriteResult} */
-export const writeImpl = ({ok, wouldBlock, closed}) => (s) => (a) => () => {
-  if (s.closed || s.writableEnded) {
-    return closed
-  }
+export const writeImpl =
+  ({ ok, wouldBlock, closed }) =>
+  (s) =>
+  (a) =>
+  () => {
+    if (s.closed || s.writableEnded) {
+      return closed;
+    }
 
-  if (s.write(a)) {
-    return ok
-  } else {
-    return wouldBlock
-  }
-}
+    if (s.write(a)) {
+      return ok;
+    } else {
+      return wouldBlock;
+    }
+  };
 
 /** @type {<ReadResult>(o: {just: (_a: unknown) => ReadResult, wouldBlock: ReadResult, closed: ReadResult}) => (s: Stream.Readable | Stream.Transform) => () => ReadResult} */
 export const readImpl =
diff --git a/src/Node.Stream.Object.purs b/src/Node.Stream.Object.purs
index c575320..5d57aea 100644
--- a/src/Node.Stream.Object.purs
+++ b/src/Node.Stream.Object.purs
@@ -28,6 +28,7 @@ data ReadResult a
   = ReadWouldBlock
   | ReadClosed
   | ReadJust a
+
 derive instance Generic (ReadResult a) _
 derive instance Functor ReadResult
 derive instance Eq a => Eq (ReadResult a)
@@ -38,9 +39,11 @@ data WriteResult
   = WriteWouldBlock
   | WriteClosed
   | WriteOk
+
 derive instance Generic WriteResult _
 derive instance Eq WriteResult
-instance Show WriteResult where show = genericShow
+instance Show WriteResult where
+  show = genericShow
 
 type ReadResultFFI a = { closed :: ReadResult a, wouldBlock :: ReadResult a, just :: a -> ReadResult a }
 type WriteResultFFI = { closed :: WriteResult, wouldBlock :: WriteResult, ok :: WriteResult }
@@ -59,10 +62,10 @@ foreign import isWritableEndedImpl :: forall s. s -> Effect Boolean
 foreign import isClosedImpl :: forall s. s -> Effect Boolean
 
 readResultFFI :: forall a. ReadResultFFI a
-readResultFFI = {closed: ReadClosed, wouldBlock: ReadWouldBlock, just: ReadJust}
+readResultFFI = { closed: ReadClosed, wouldBlock: ReadWouldBlock, just: ReadJust }
 
 writeResultFFI :: WriteResultFFI
-writeResultFFI = {closed: WriteClosed, wouldBlock: WriteWouldBlock, ok: WriteOk}
+writeResultFFI = { closed: WriteClosed, wouldBlock: WriteWouldBlock, ok: WriteOk }
 
 class Stream :: Type -> Constraint
 class Stream s where
@@ -117,11 +120,11 @@ else instance (Write s a) => Write s a where
   write s a = write s a
   end s = end s
 
-withErrorST :: forall s. Stream s => s -> Effect {cancel :: Effect Unit, error :: STRef Global (Maybe Error)}
+withErrorST :: forall s. Stream s => s -> Effect { cancel :: Effect Unit, error :: STRef Global (Maybe Error) }
 withErrorST s = do
   error <- liftST $ STRef.new Nothing
   cancel <- flip (Event.once errorH) s \e -> void $ liftST $ STRef.write (Just e) error
-  pure {error, cancel}
+  pure { error, cancel }
 
 fromBufferReadable :: forall r. Stream.Readable r -> Readable Buffer
 fromBufferReadable = unsafeCoerce
@@ -147,7 +150,7 @@ awaitReadableOrClosed s = do
   ended <- liftEffect $ isReadableEnded s
   readable <- liftEffect $ isReadable s
   when (not ended && not closed && not readable)
-    $ liftEither =<< parOneOf [onceAff0 readableH s $> Right unit, onceAff0 closeH s $> Right unit, Left <$> onceAff1 errorH s]
+    $ liftEither =<< parOneOf [ onceAff0 readableH s $> Right unit, onceAff0 closeH s $> Right unit, Left <$> onceAff1 errorH s ]
 
 awaitWritableOrClosed :: forall s a. Write s a => s -> Aff Unit
 awaitWritableOrClosed s = do
@@ -155,7 +158,7 @@ awaitWritableOrClosed s = do
   ended <- liftEffect $ isWritableEnded s
   writable <- liftEffect $ isWritable s
   when (not ended && not closed && not writable)
-    $ liftEither =<< parOneOf [onceAff0 drainH s $> Right unit, onceAff0 closeH s $> Right unit, Left <$> onceAff1 errorH s]
+    $ liftEither =<< parOneOf [ onceAff0 drainH s $> Right unit, onceAff0 closeH s $> Right unit, Left <$> onceAff1 errorH s ]
 
 onceAff0 :: forall e. EventHandle0 e -> e -> Aff Unit
 onceAff0 h emitter = makeAff \res -> do
diff --git a/src/Pipes.Collect.purs b/src/Pipes.Collect.purs
index 9bbd964..b2d72c8 100644
--- a/src/Pipes.Collect.purs
+++ b/src/Pipes.Collect.purs
@@ -2,17 +2,81 @@ module Pipes.Collect where
 
 import Prelude
 
-import Control.Monad.Rec.Class (class MonadRec)
+import Control.Monad.Maybe.Trans (MaybeT(..), runMaybeT)
+import Control.Monad.Rec.Class (class MonadRec, Step(..), tailRecM)
 import Control.Monad.ST.Class (liftST)
+import Control.Monad.Trans.Class (lift)
 import Data.Array.ST as Array.ST
+import Data.Either (hush)
+import Data.HashMap (HashMap)
+import Data.HashMap as HashMap
+import Data.Hashable (class Hashable)
+import Data.List (List)
+import Data.List as List
+import Data.Map (Map)
+import Data.Map as Map
+import Data.Maybe (fromMaybe)
+import Data.Tuple.Nested (type (/\), (/\))
 import Effect.Class (class MonadEffect, liftEffect)
-import Pipes (for) as Pipes
+import Foreign.Object (Object)
+import Foreign.Object.ST as Object.ST
+import Foreign.Object.ST.Unsafe as Object.ST.Unsafe
+import Pipes (next) as Pipes
 import Pipes.Core (Producer)
-import Pipes.Core (runEffect) as Pipes
 
--- | Traverse a pipe, collecting into a mutable array with constant stack usage
-collectArray :: forall a m. MonadRec m => MonadEffect m => Producer a m Unit -> m (Array a)
-collectArray p = do
+-- | Fold every value produced
+-- |
+-- | Uses `MonadRec`, supporting producers of arbitrary length.
+fold :: forall a b m. MonadRec m => (b -> a -> b) -> b -> Producer a m Unit -> m b
+fold f b p =
+  let
+    insertNext b' p' = runMaybeT do
+      a /\ p'' <- MaybeT $ hush <$> Pipes.next p'
+      pure $ Loop $ f b' a /\ p''
+  in
+    flip tailRecM (b /\ p) \(b' /\ p') -> fromMaybe (Done b') <$> insertNext b' p'
+
+-- | Fold every value produced with a monadic action
+-- |
+-- | Uses `MonadRec`, supporting producers of arbitrary length.
+traverse :: forall a b m. MonadRec m => (b -> a -> m b) -> b -> Producer a m Unit -> m b
+traverse f b p =
+  let
+    insertNext b' p' = runMaybeT do
+      a /\ p'' <- MaybeT $ hush <$> Pipes.next p'
+      b'' <- lift $ f b' a
+      pure $ Loop $ b'' /\ p''
+  in
+    flip tailRecM (b /\ p) \(b' /\ p') -> fromMaybe (Done b') <$> insertNext b' p'
+
+-- | Execute a monadic action on every item in a producer.
+-- |
+-- | Uses `MonadRec`, supporting producers of arbitrary length.
+foreach :: forall a m. MonadRec m => (a -> m Unit) -> Producer a m Unit -> m Unit
+foreach f = traverse (const f) unit
+
+-- | Collect all values from a `Producer` into an array.
+toArray :: forall a m. MonadRec m => MonadEffect m => Producer a m Unit -> m (Array a)
+toArray p = do
   st <- liftEffect $ liftST $ Array.ST.new
-  Pipes.runEffect $ Pipes.for p \a -> void $ liftEffect $ liftST $ Array.ST.push a st
+  foreach (void <<< liftEffect <<< liftST <<< flip Array.ST.push st) p
   liftEffect $ liftST $ Array.ST.unsafeFreeze st
+
+-- | Collect all values from a `Producer` into a list.
+toList :: forall a m. MonadRec m => MonadEffect m => Producer a m Unit -> m (List a)
+toList = map List.reverse <<< fold (flip List.Cons) List.Nil
+
+-- | Collect all values from a `Producer` into a Javascript Object.
+toObject :: forall a m. MonadRec m => MonadEffect m => Producer (String /\ a) m Unit -> m (Object a)
+toObject p = do
+  st <- liftEffect $ liftST $ Object.ST.new
+  foreach (\(k /\ v) -> void $ liftEffect $ liftST $ Object.ST.poke k v st) p
+  liftEffect $ liftST $ Object.ST.Unsafe.unsafeFreeze st
+
+-- | Collect all values from a `Producer` into a `HashMap`
+toHashMap :: forall k v m. Hashable k => MonadRec m => Producer (k /\ v) m Unit -> m (HashMap k v)
+toHashMap = fold (\map (k /\ v) -> HashMap.insert k v map) HashMap.empty
+
+-- | Collect all values from a `Producer` into a `Map`
+toMap :: forall k v m. Ord k => MonadRec m => Producer (k /\ v) m Unit -> m (Map k v)
+toMap = fold (\map (k /\ v) -> Map.insert k v map) Map.empty
diff --git a/src/Pipes.Node.FS.purs b/src/Pipes.Node.FS.purs
index a73616c..f2b1281 100644
--- a/src/Pipes.Node.FS.purs
+++ b/src/Pipes.Node.FS.purs
@@ -23,8 +23,10 @@ import Prim.Row (class Union)
 -- | into `Producer (Maybe a)`, emitting `Nothing` before exiting.
 write
   :: forall r trash
-  . Union r trash WriteStreamOptions
-  => Record r -> FilePath -> Consumer (Maybe Buffer) Aff Unit
+   . Union r trash WriteStreamOptions
+  => Record r
+  -> FilePath
+  -> Consumer (Maybe Buffer) Aff Unit
 write o p = do
   w <- liftEffect $ FS.Stream.createWriteStream' p o
   fromWritable $ O.fromBufferWritable w
@@ -33,19 +35,19 @@ write o p = do
 -- |
 -- | `write {flags: "wx"}`
 create :: FilePath -> Consumer (Maybe Buffer) Aff Unit
-create = write {flags: "wx"}
+create = write { flags: "wx" }
 
 -- | Open a file in write mode, truncating it if the file already exists.
 -- |
 -- | `write {flags: "w"}`
 truncate :: FilePath -> Consumer (Maybe Buffer) Aff Unit
-truncate = write {flags: "w"}
+truncate = write { flags: "w" }
 
 -- | Open a file in write mode, appending written contents if the file already exists.
 -- |
 -- | `write {flags: "a"}`
 append :: FilePath -> Consumer (Maybe Buffer) Aff Unit
-append = write {flags: "a"}
+append = write { flags: "a" }
 
 -- | Creates a `fs.Readable` stream for the file at the given path.
 -- |
diff --git a/src/Pipes.Node.Stream.purs b/src/Pipes.Node.Stream.purs
index d07dbc9..7c27a9f 100644
--- a/src/Pipes.Node.Stream.purs
+++ b/src/Pipes.Node.Stream.purs
@@ -30,19 +30,20 @@ fromReadable r =
       liftEffect rmErrorListener
       pure $ Done unit
 
-    go {error, cancel} = do
+    go { error, cancel } = do
       liftAff $ delay $ wrap 0.0
       err <- liftEffect $ liftST $ STRef.read error
       for_ err throwError
 
       res <- liftEffect $ O.read r
       case res of
-        O.ReadJust a -> yield (Just a) $> Loop {error, cancel}
-        O.ReadWouldBlock -> lift (O.awaitReadableOrClosed r) $> Loop {error, cancel}
+        O.ReadJust a -> yield (Just a) $> Loop { error, cancel }
+        O.ReadWouldBlock -> lift (O.awaitReadableOrClosed r) $> Loop { error, cancel }
         O.ReadClosed -> yield Nothing *> cleanup cancel
-  in do
-    e <- liftEffect $ O.withErrorST r
-    tailRecM go e
+  in
+    do
+      e <- liftEffect $ O.withErrorST r
+      tailRecM go e
 
 -- | Convert a `Writable` stream to a `Pipe`.
 -- |
@@ -56,7 +57,7 @@ fromWritable w =
       liftEffect $ O.end w
       pure $ Done unit
 
-    go {error, cancel} = do
+    go { error, cancel } = do
       liftAff $ delay $ wrap 0.0
       err <- liftEffect $ liftST $ STRef.read error
       for_ err throwError
@@ -67,14 +68,15 @@ fromWritable w =
         Just a -> do
           res <- liftEffect $ O.write w a
           case res of
-            O.WriteOk -> pure $ Loop {error, cancel}
+            O.WriteOk -> pure $ Loop { error, cancel }
             O.WriteWouldBlock -> do
               liftAff (O.awaitWritableOrClosed w)
-              pure $ Loop {error, cancel}
+              pure $ Loop { error, cancel }
             O.WriteClosed -> cleanup cancel
-  in do
-    r <- liftEffect $ O.withErrorST w
-    tailRecM go r
+  in
+    do
+      r <- liftEffect $ O.withErrorST w
+      tailRecM go r
 
 -- | Convert a `Transform` stream to a `Pipe`.
 -- |
@@ -94,7 +96,7 @@ fromTransform t =
         O.ReadJust a -> yield (Just a)
         O.ReadWouldBlock -> pure unit
         O.ReadClosed -> yield Nothing *> pure unit
-    go {error, cancel} = do
+    go { error, cancel } = do
       liftAff $ delay $ wrap 0.0
       err <- liftEffect $ liftST $ STRef.read error
       for_ err throwError
@@ -107,13 +109,14 @@ fromTransform t =
           yieldFromReadableHalf
           case res of
             O.WriteClosed -> cleanup cancel
-            O.WriteOk -> pure $ Loop {error, cancel}
+            O.WriteOk -> pure $ Loop { error, cancel }
             O.WriteWouldBlock -> do
               lift (O.awaitWritableOrClosed t)
-              pure $ Loop {error, cancel}
-  in do
-    r <- liftEffect $ O.withErrorST t
-    tailRecM go r
+              pure $ Loop { error, cancel }
+  in
+    do
+      r <- liftEffect $ O.withErrorST t
+      tailRecM go r
 
 -- | Given a `Producer` of values, wrap them in `Just`.
 -- |
diff --git a/src/Pipes.String.purs b/src/Pipes.String.purs
index 592fb6f..d955ce1 100644
--- a/src/Pipes.String.purs
+++ b/src/Pipes.String.purs
@@ -33,7 +33,7 @@ split pat = do
       Nothing -> void $ liftEffect $ liftST $ Array.ST.push chunk buf
       Just ix -> do
         let
-          {before, after} = String.splitAt ix chunk
+          { before, after } = String.splitAt ix chunk
         len <- liftEffect $ liftST $ Array.ST.length buf
         buf' <- liftEffect $ liftST $ Array.ST.splice 0 len [] buf
         lift $ yield $ Just $ (fold buf') <> before
diff --git a/test/Test/Main.purs b/test/Test/Main.purs
index fab2200..0315a5a 100644
--- a/test/Test/Main.purs
+++ b/test/Test/Main.purs
@@ -8,6 +8,7 @@ import Effect.Aff (launchAff_)
 import Test.Pipes.Node.Stream as Test.Pipes.Node.Stream
 import Test.Pipes.Node.Buffer as Test.Pipes.Node.Buffer
 import Test.Pipes.Node.FS as Test.Pipes.Node.FS
+import Test.Pipes.Collect as Test.Pipes.Collect
 import Test.Spec.Reporter (specReporter)
 import Test.Spec.Runner (defaultConfig, runSpec')
 
@@ -16,3 +17,4 @@ main = launchAff_ $ runSpec' (defaultConfig { failFast = true, timeout = Nothing
   Test.Pipes.Node.Stream.spec
   Test.Pipes.Node.Buffer.spec
   Test.Pipes.Node.FS.spec
+  Test.Pipes.Collect.spec
diff --git a/test/Test/Pipes.Collect.purs b/test/Test/Pipes.Collect.purs
new file mode 100644
index 0000000..efbe8b8
--- /dev/null
+++ b/test/Test/Pipes.Collect.purs
@@ -0,0 +1,111 @@
+module Test.Pipes.Collect where
+
+import Prelude
+
+import Control.Monad.Gen (chooseInt)
+import Control.Monad.Rec.Class (Step(..), tailRecM)
+import Control.Monad.ST as ST
+import Control.Monad.ST.Ref as STRef
+import Data.Array as Array
+import Data.Bifunctor (lmap)
+import Data.HashMap (HashMap)
+import Data.HashMap as HashMap
+import Data.List (List)
+import Data.List as List
+import Data.Map (Map)
+import Data.Map as Map
+import Data.Maybe (Maybe(..))
+import Data.Traversable (traverse)
+import Data.Tuple.Nested (type (/\), (/\))
+import Effect.Aff (Aff)
+import Effect.Class (liftEffect)
+import Effect.Unsafe (unsafePerformEffect)
+import Foreign.Object (Object)
+import Foreign.Object as Object
+import Pipes (yield)
+import Pipes.Collect as Pipes.Collect
+import Pipes.Core (Producer)
+import Test.QuickCheck.Gen (randomSampleOne)
+import Test.Spec (Spec, describe, it)
+import Test.Spec.Assertions (shouldEqual)
+
+testData
+  :: { array :: Array (Int /\ Int)
+     , list :: List (Int /\ Int)
+     , strarray :: Array (String /\ Int)
+     , object :: Object Int
+     , map :: Map Int Int
+     , hashMap :: HashMap Int Int
+     , stream :: Producer (Int /\ Int) Aff Unit
+     , streamStr :: Producer (String /\ Int) Aff Unit
+     }
+testData =
+  unsafePerformEffect $ do
+    array <-
+      flip traverse (Array.range 0 99999) \k -> do
+        v <- liftEffect $ randomSampleOne $ chooseInt 0 99999
+        pure $ k /\ v
+    let
+      strarray = lmap show <$> array
+      object = Object.fromFoldable strarray
+
+      map' :: forall m. m -> (Int -> Int -> m -> m) -> m
+      map' empty insert = ST.run do
+        st <- STRef.new empty
+        ST.foreach array \(k /\ v) -> void $ STRef.modify (insert k v) st
+        STRef.read st
+      hashMap = map' HashMap.empty HashMap.insert
+      map = map' Map.empty Map.insert
+    pure
+      { array
+      , strarray
+      , list: List.fromFoldable array
+      , object
+      , hashMap
+      , map
+      , stream: flip tailRecM 0 \ix -> case Array.index array ix of
+          Just a -> yield a $> Loop (ix + 1)
+          Nothing -> pure $ Done unit
+      , streamStr: flip tailRecM 0 \ix -> case Array.index strarray ix of
+          Just a -> yield a $> Loop (ix + 1)
+          Nothing -> pure $ Done unit
+      }
+
+spec :: Spec Unit
+spec =
+  describe "Test.Pipes.Collect" do
+    describe "toArray" do
+      it "collects an array" do
+        act <- Pipes.Collect.toArray testData.stream
+        act `shouldEqual` testData.array
+      it "empty ok" do
+        act :: Array Int <- Pipes.Collect.toArray (pure unit)
+        act `shouldEqual` []
+    describe "toObject" do
+      it "collects" do
+        act <- Pipes.Collect.toObject $ testData.streamStr
+        act `shouldEqual` testData.object
+      it "empty ok" do
+        act :: Object Int <- Pipes.Collect.toObject (pure unit)
+        act `shouldEqual` Object.empty
+    describe "toMap" do
+      it "collects" do
+        act <- Pipes.Collect.toMap testData.stream
+        act `shouldEqual` testData.map
+      it "empty ok" do
+        act :: Map String Int <- Pipes.Collect.toMap (pure unit)
+        act `shouldEqual` Map.empty
+    describe "toHashMap" do
+      it "collects" do
+        act <- Pipes.Collect.toHashMap testData.stream
+        act `shouldEqual` testData.hashMap
+      it "empty ok" do
+        act :: HashMap String Int <- Pipes.Collect.toHashMap (pure unit)
+        act `shouldEqual` HashMap.empty
+    describe "toList" do
+      it "collects" do
+        act <- Pipes.Collect.toList testData.stream
+        act `shouldEqual` testData.list
+      it "empty ok" do
+        act :: List (String /\ Int) <- Pipes.Collect.toList (pure unit)
+        act `shouldEqual` List.Nil
diff --git a/test/Test/Pipes.Node.Buffer.purs b/test/Test/Pipes.Node.Buffer.purs
index 3f94a9c..5cea4c9 100644
--- a/test/Test/Pipes.Node.Buffer.purs
+++ b/test/Test/Pipes.Node.Buffer.purs
@@ -27,6 +27,7 @@ import Test.Spec (Spec, describe, it)
 import Test.Spec.Assertions (fail, shouldEqual)
 
 data BufferJunk = BufferJunk Buffer
+
 instance Arbitrary BufferJunk where
   arbitrary = sized \s -> do
     ns <- vectorOf s (chooseInt 0 7)
@@ -36,6 +37,7 @@ instance Arbitrary BufferJunk where
       pure $ BufferJunk buf
 
 data BufferUTF8 = BufferUTF8 String Buffer
+
 instance Arbitrary BufferUTF8 where
   arbitrary = do
     s <- genAsciiString
@@ -43,27 +45,27 @@ instance Arbitrary BufferUTF8 where
 
 spec :: Spec Unit
 spec = describe "Pipes.Node.Buffer" do
-    describe "toString" do
-      it "fails when encoding wrong" do
-        vals <- Pipes.each <$> (map \(BufferJunk b) -> b) <$> liftEffect (randomSample' 10 arbitrary)
-        let
-          uut = Pipes.runEffect $ vals >-> Pipes.Node.Buffer.toString UTF8 >-> Pipes.drain
-          ok = do
-            uut
-            fail "Should have thrown"
-          err _ = pure unit
-        catchError ok err
-      it "junk OK in hex" do
-        vals <- Pipes.each <$> (map \(BufferJunk b) -> b) <$> liftEffect (randomSample' 10 arbitrary)
-        Pipes.runEffect $ vals >-> Pipes.Node.Buffer.toString Hex >-> Pipes.drain
-      it "UTF8 ok" do
-        vals <- (map \(BufferUTF8 s b) -> s /\ b) <$> liftEffect (randomSample' 100 arbitrary)
-        let
-          bufs = Pipes.each $ snd <$> vals
-          strs = fst <$> vals
-        act <- Array.fromFoldable <$> Pipes.toListM (bufs >-> Pipes.Node.Buffer.toString UTF8)
-        act `shouldEqual` strs
-    describe "fromString" do
-      it "ok" do
-        vals <- Pipes.each <$> liftEffect (randomSample' 100 genAsciiString)
-        Pipes.runEffect $ vals >-> Pipes.Node.Buffer.fromString UTF8 >-> Pipes.drain
+  describe "toString" do
+    it "fails when encoding wrong" do
+      vals <- Pipes.each <$> (map \(BufferJunk b) -> b) <$> liftEffect (randomSample' 10 arbitrary)
+      let
+        uut = Pipes.runEffect $ vals >-> Pipes.Node.Buffer.toString UTF8 >-> Pipes.drain
+        ok = do
+          uut
+          fail "Should have thrown"
+        err _ = pure unit
+      catchError ok err
+    it "junk OK in hex" do
+      vals <- Pipes.each <$> (map \(BufferJunk b) -> b) <$> liftEffect (randomSample' 10 arbitrary)
+      Pipes.runEffect $ vals >-> Pipes.Node.Buffer.toString Hex >-> Pipes.drain
+    it "UTF8 ok" do
+      vals <- (map \(BufferUTF8 s b) -> s /\ b) <$> liftEffect (randomSample' 100 arbitrary)
+      let
+        bufs = Pipes.each $ snd <$> vals
+        strs = fst <$> vals
+      act <- Array.fromFoldable <$> Pipes.toListM (bufs >-> Pipes.Node.Buffer.toString UTF8)
+      act `shouldEqual` strs
+  describe "fromString" do
+    it "ok" do
+      vals <- Pipes.each <$> liftEffect (randomSample' 100 genAsciiString)
+      Pipes.runEffect $ vals >-> Pipes.Node.Buffer.fromString UTF8 >-> Pipes.drain
diff --git a/test/Test/Pipes.Node.FS.purs b/test/Test/Pipes.Node.FS.purs
index 5f95b86..6196e0e 100644
--- a/test/Test/Pipes.Node.FS.purs
+++ b/test/Test/Pipes.Node.FS.purs
@@ -24,63 +24,63 @@ import Test.Spec.Assertions (fail, shouldEqual)
 
 spec :: Spec Unit
 spec = describe "Pipes.Node.FS" do
-    describe "read" do
-      around tmpFile $ it "fails if the file does not exist" \p -> do
-        flip catchError (const $ pure unit) do
-          Pipes.runEffect $ Pipes.Node.FS.read p >-> Pipes.drain
-          fail "should have thrown"
-      around tmpFile $ it "reads ok" \p -> do
-        liftEffect $ FS.writeTextFile UTF8 p "foo"
-        s <- fold <$> Pipes.toListM (Pipes.Node.FS.read p >-> unEOS >-> Pipes.Node.Buffer.toString UTF8)
-        s `shouldEqual` "foo"
-      around tmpFile $ it "fails if the file already exists" \p -> do
-        liftEffect $ FS.writeTextFile UTF8 "foo" p
-        flip catchError (const $ pure unit) do
-          Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.create p
-          fail "should have thrown"
-    describe "create" do
-      around tmpFile $ it "creates the file when not exists" \p -> do
+  describe "read" do
+    around tmpFile $ it "fails if the file does not exist" \p -> do
+      flip catchError (const $ pure unit) do
+        Pipes.runEffect $ Pipes.Node.FS.read p >-> Pipes.drain
+        fail "should have thrown"
+    around tmpFile $ it "reads ok" \p -> do
+      liftEffect $ FS.writeTextFile UTF8 p "foo"
+      s <- fold <$> Pipes.toListM (Pipes.Node.FS.read p >-> unEOS >-> Pipes.Node.Buffer.toString UTF8)
+      s `shouldEqual` "foo"
+    around tmpFile $ it "fails if the file already exists" \p -> do
+      liftEffect $ FS.writeTextFile UTF8 "foo" p
+      flip catchError (const $ pure unit) do
         Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.create p
-        contents <- liftEffect $ FS.readTextFile UTF8 p
-        contents `shouldEqual` "foo"
-      around tmpFile $ it "fails if the file already exists" \p -> do
-        liftEffect $ FS.writeTextFile UTF8 "foo" p
-        flip catchError (const $ pure unit) do
-          Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.create p
-          fail "should have thrown"
-    describe "append" do
-      around tmpFile $ it "creates the file when not exists" \p -> do
-        Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
-        contents <- liftEffect $ FS.readTextFile UTF8 p
-        contents `shouldEqual` "foo"
-      around tmpFile $ it "appends" \p -> do
-        Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
-        Pipes.runEffect $ withEOS (yield "\n" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
-        Pipes.runEffect $ withEOS (yield "bar" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
-        contents <- liftEffect $ FS.readTextFile UTF8 p
-        contents `shouldEqual` "foo\nbar"
-    describe "truncate" do
-      around tmpFile $ it "creates the file when not exists" \p -> do
-        Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
-        contents <- liftEffect $ FS.readTextFile UTF8 p
-        contents `shouldEqual` "foo"
-      around tmpFile $ it "overwrites contents" \p -> do
-        Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
-        Pipes.runEffect $ withEOS (yield "bar" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
-        contents <- liftEffect $ FS.readTextFile UTF8 p
-        contents `shouldEqual` "bar"
-    around tmpFiles $ it "json lines >-> parse >-> _.foo >-> write" \(a /\ b) -> do
-      let
-        exp = [{foo: "a"}, {foo: "bar"}, {foo: "123"}]
-      liftEffect $ FS.writeTextFile UTF8 a $ intercalate "\n" $ writeJSON <$> exp
-      Pipes.runEffect $
-        Pipes.Node.FS.read a
+        fail "should have thrown"
+  describe "create" do
+    around tmpFile $ it "creates the file when not exists" \p -> do
+      Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.create p
+      contents <- liftEffect $ FS.readTextFile UTF8 p
+      contents `shouldEqual` "foo"
+    around tmpFile $ it "fails if the file already exists" \p -> do
+      liftEffect $ FS.writeTextFile UTF8 "foo" p
+      flip catchError (const $ pure unit) do
+        Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.create p
+        fail "should have thrown"
+  describe "append" do
+    around tmpFile $ it "creates the file when not exists" \p -> do
+      Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
+      contents <- liftEffect $ FS.readTextFile UTF8 p
+      contents `shouldEqual` "foo"
+    around tmpFile $ it "appends" \p -> do
+      Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
+      Pipes.runEffect $ withEOS (yield "\n" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
+      Pipes.runEffect $ withEOS (yield "bar" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.append p
+      contents <- liftEffect $ FS.readTextFile UTF8 p
+      contents `shouldEqual` "foo\nbar"
+  describe "truncate" do
+    around tmpFile $ it "creates the file when not exists" \p -> do
+      Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
+      contents <- liftEffect $ FS.readTextFile UTF8 p
+      contents `shouldEqual` "foo"
+    around tmpFile $ it "overwrites contents" \p -> do
+      Pipes.runEffect $ withEOS (yield "foo" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
+      Pipes.runEffect $ withEOS (yield "bar" >-> Pipes.Node.Buffer.fromString UTF8) >-> Pipes.Node.FS.truncate p
+      contents <- liftEffect $ FS.readTextFile UTF8 p
+      contents `shouldEqual` "bar"
+  around tmpFiles $ it "json lines >-> parse >-> _.foo >-> write" \(a /\ b) -> do
+    let
+      exp = [ { foo: "a" }, { foo: "bar" }, { foo: "123" } ]
+    liftEffect $ FS.writeTextFile UTF8 a $ intercalate "\n" $ writeJSON <$> exp
+    Pipes.runEffect $
+      Pipes.Node.FS.read a
         >-> inEOS (Pipes.Node.Buffer.toString UTF8)
         >-> Pipes.String.split (wrap "\n")
-        >-> inEOS (jsonParse @{foo :: String})
+        >-> inEOS (jsonParse @{ foo :: String })
         >-> inEOS (Pipes.map _.foo)
         >-> Pipes.Util.intersperse "\n"
         >-> inEOS (Pipes.Node.Buffer.fromString UTF8)
         >-> Pipes.Node.FS.create b
-      act <- liftEffect $ FS.readTextFile UTF8 b
-      act `shouldEqual` "a\nbar\n123"
+    act <- liftEffect $ FS.readTextFile UTF8 b
+    act `shouldEqual` "a\nbar\n123"
diff --git a/test/Test/Pipes.Node.Stream.purs b/test/Test/Pipes.Node.Stream.purs
index 8e0c1ab..cd8f1b2 100644
--- a/test/Test/Pipes.Node.Stream.purs
+++ b/test/Test/Pipes.Node.Stream.purs
@@ -96,7 +96,7 @@ spec =
               str :: String <- genAlphaString
               num :: Int <- arbitrary
               stuff :: Array String <- arbitrary
-              pure {str, num, stuff}
+              pure { str, num, stuff }
           objs <- liftEffect (randomSample' 1 obj)
           let
             exp = fold (writeJSON <$> objs)
@@ -108,14 +108,14 @@ spec =
     describe "Transform" do
       it "gzip" do
         let
-          json = yield $ writeJSON {foo: "bar"}
+          json = yield $ writeJSON { foo: "bar" }
           exp = "1f8b0800000000000003ab564acbcf57b2524a4a2c52aa0500eff52bfe0d000000"
         gzip <- S.fromTransform <$> O.fromBufferTransform <$> liftEffect (Zlib.toDuplex <$> Zlib.createGzip)
         outs :: List.List String <- Pipes.toListM (S.withEOS (json >-> Pipes.Buffer.fromString UTF8) >-> gzip >-> S.unEOS >-> Pipes.Buffer.toString Hex)
         fold outs `shouldEqual` exp
       around tmpFiles
         $ it "file >-> gzip >-> file >-> gunzip" \(a /\ b) -> do
-            liftEffect $ FS.writeTextFile UTF8 a $ writeJSON [1, 2, 3, 4]
+            liftEffect $ FS.writeTextFile UTF8 a $ writeJSON [ 1, 2, 3, 4 ]
             areader <- liftEffect $ reader a
             bwritestream /\ bwriter <- liftEffect $ writer b
             gzip <- S.fromTransform <$> O.fromBufferTransform <$> liftEffect (Zlib.toDuplex <$> Zlib.createGzip)
@@ -125,7 +125,7 @@ spec =
             gunzip <- S.fromTransform <$> O.fromBufferTransform <$> liftEffect (Zlib.toDuplex <$> Zlib.createGunzip)
             breader <- liftEffect $ reader b
             nums <- Pipes.toListM (breader >-> gunzip >-> S.unEOS >-> Pipes.Buffer.toString UTF8 >-> jsonParse @(Array Int) >-> Pipes.mapFoldable identity)
-            Array.fromFoldable nums `shouldEqual` [1, 2, 3, 4]
+            Array.fromFoldable nums `shouldEqual` [ 1, 2, 3, 4 ]
       around tmpFile $ it "file >-> discardTransform" \(p :: String) -> do
         liftEffect $ FS.writeTextFile UTF8 p "foo"
         r <- reader p
@@ -137,4 +137,4 @@ spec =
         r <- reader p
         chars' <- liftEffect charsTransform
         out :: List.List String <- Pipes.toListM $ r >-> S.inEOS (Pipes.Buffer.toString UTF8) >-> S.fromTransform chars' >-> S.unEOS
-        out `shouldEqual` List.fromFoldable ["f", "o", "o", " ", "b", "a", "r"]
+        out `shouldEqual` List.fromFoldable [ "f", "o", "o", " ", "b", "a", "r" ]